Implementation of EU law is vital for European integration. The EU implementation record however up until now shows that there are serious implementation deficits. Although the EU in response to these deficits has piled op strategies and instruments to improve the overall implementation, we still do not know how big the compliance problem of the EU is. The nature and seriousness of compliance deficits are until now the ‘known unknowns’. This paper looks into two issues that are important if we want to improve implementation and compliance rates of EU law. First of all it addresses the question of how to gather information on implementation and compliance as a basis for enforcement policies and secondly is appraises the EU’s enforcement policies, set up to improve the implementation of EU Law currently in place. The paper concludes that present EU strategies and tools to promote compliance broadly follow the enforcement-school approach with some management-school elements. It also concludes that the information basis for these strategies is quite weak and that they are not based on a deep understanding of what motives underlie noncompliant behaviour. The strategies and instruments rely strongly on repression by sanctions as well. A better understanding of the how and the why of non-compliance could improve the effectiveness of the present policies in place – more positive and communicative approaches to non-compliance could well complement present strategies and instruments.